WASHINGTON — The first U.S. Army infantry troops are heading to Haiti today as the military ramps up what Secretary of State Hillary Rodham Clinton called "a full-court press" to provide earthquake relief.

The first group of soldiers — a little more than 100 — from the 82nd Airborne Division will leave Fort Bragg in North Carolina later today, the Army said. The troops will find locations to set up tents and other essentials before the arrival of another 800 personnel from the division on Friday.

They come on top of some 2,200 Marines, also to be sent, as the military prepares to help with security needs, search and rescue and the delivery of humanitarian supplies. More than a half dozen U.S. military ships are expected to help, with the largest, the aircraft carrier USS Carl Vinson, arriving today.

Appearing on morning TV network news shows, Clinton said it's too early to make a firm estimate of the number of deaths in the wake of Tuesday's devastating, earthquake.

But she said officials know that about 3 million people, including 45,000 Americans, have been affected and that "tens of thousands, we fear, are dead."